Which of the following sequences best represents the primary steps of the scientific method as applied in nutrition research?

Which statement best captures why nutrition researchers prefer numerical data that can be analyzed statistically?

A laboratory study in rats shows that compound Y improves insulin sensitivity by affecting liver enzyme Z. Which human measurements would best translate this mechanistic evidence into a feasible human follow-up study?

Which observational study type is most appropriate when a researcher wants to study a rare disease and compare prior exposures between those with and without the disease?

Which of the following sequences best represents the primary steps of the scientific method as applied in nutrition research?

Transform the observation 'People who eat late-night snacks have higher BMI' into a refined, testable hypothesis suitable for a randomized trial.

A published trial testing a vitamin supplement reported subjective improvement in symptoms only in the treatment arm but did not use a placebo and participants were aware of their assignment. Which bias is most likely inflating the reported treatment effect, and how would introducing a placebo and blinding change interpretation?

Which of the following statements correctly contrasts experimental clinical trials with observational studies in nutrition?

In a 5-year cohort, 60 of 500 supplement users developed outcome Z and 30 of 500 non-users developed outcome Z. Calculate the risk ratio of outcome Z for supplement users versus non-users.

An observational study reports that communities with higher fermented food consumption have lower antibiotic-resistant infections. As a reviewer, what multi-step critique and follow-up would you recommend to strengthen causal inference?